Manufacture of artificial threads, ribbons, and like materials



H. DREYFUS Sept. 22, 1936.

MANUFACTURE OF ARTIFICIAL THREADS, RIBBONS, AND LIKE MATERIALS FiledFeb. 18, 1932 HENR DREYFUS INVENTOR QCM n-r -r/\n MEV Patented Sept. 22,1936 e-ATENT" oFFicE MANUFACTURE OF ARTIFICIAL THREADS,

RIBBONS, AND LIKE MATERIALS Henry Dreyfus, London, England ApplicationFebruary 18, 1932, Serial No. 593,859 In Great Britain March 27, 1931' 8Claims.

. which the materials are stretched while passing through a liquidmedium.

When filaments, threads and the like of cellulose acetate or otherderivatives of cellulose are caused to pass through a liquid medium, byvirtue of the relative motion between the materials and the medium, africtional force is set up which tends to oppose the motion of thematerials. In the case of a liquid medium of relatively low viscosity,for example Water, the frictional resistance may be comparatively small.A far greater efiect however is obtained when liquid media ofcomparatively high Viscosity, for example aqueous solutions of sugars,polysaccharides or other polyhydric alcohols are employed.

I have now found that this frictional eifect may be turned to greatadvantage by causing the liquid to move in such a direction as to retardthe motion of the materials to a greater extent than would occur werethe liquid at rest. By this means the magnitude and location of theextension which the materials undergo in their course through the'liquidmedium may readily be controlled. Thus, for example, provided thematerials are sufficiently plastic, by imparting to the liquid at agiven point along the path of the materials a greater velocity than itpossesses elsewhere along the path a relatively great extension may beproduced between said point and the point of application of the tension.This ability to control the distribution of extension along the path ofthe materials is of great advantage, particularly when applied to acoagulating bath employed in the production of the materials by spinningprocesses. Filaments emerging from a spinning jet increase in strengthas coagulation progresses, and it is naturally advantageous to be ableto control the process so that relatively great extension occurs at apoint where the materials have acquired considerable tensile strength.

According therefore to the present invention filaments, threads, fibres,yarns, ribbons and the like of cellulose acetate or other derivatives ofcellulose are caused to pass'through liquid media moving in such adirection as to exert a greater drag upon the materials than if theliquid were at rest. The process of the invention may be carried outcontinuously with the production of the materials by a wet or dryspinning process or to fully formed materials.

as a separate treatment applied, for example, The process of theinvention is particularly valuable when applied as a step in the actualproduction of the mate.- rials by a wet spinning process, when forexample the coagulating bath itself is set in motion. This aspect of theinvention will therefore be described in detail. a

The invention contemplates the manufacture of materials made'of orcontaining cellulose ace- 1,0, tate or other derivatives of cellulose,for example other esters of cellulose such as cellulose nitrate,formate, propionate or butyrate, ethers of cellulose, for examplemethyLethyl or benzyl cellulose, mixed esters e. g. cellulosenitroacetate, l5 and mixed ethers and ether-esters. The manufactureshould be such that the resulting products have a more or lesscontinuous gel structure. 7 The spinning solution may be made bydissolving the cellulose acetate or other derivative of 20 cellulose inany suitable solvent. examples of suitable organic solvents forcellulose acetate mention may be made of acetone, acetic acid, andmixtures of ethylene or methylene dichloride with ethyl or methylalcohol. The spinning solu- 25 tion may contain relatively high boilingsolvents or even plasticizers, for instance diacetone al cohol, ethyllactate or diethyl tartrate. It is of advantage, with a. view toobtaining products of more or less continuous gel structure, for the 39p nn n l n to tain solvents o Swellin agents for the cellulosederivative, which are less soluble in the coagulating medium than thesolvent which constitutes the bulk of the spinning solution. 1 Thepercentage of cellulose derivative in the spinning solution may varywithin wide limits, but general concentrations of from 15 to 30%, andparticularly about 25%, have been found suitable. Obviously the solutionshould be neither so dilute 9 that excessive shrinkage occurs, nor soconcentrated as to render spinning impracticable. Where extrusion occursat temperatures above normal, .or where the characteristics of thecellulose derivative are such that solutions of comparatively lowviscosity are obtained, higher concentrations than are otherwisepermissible may be employed.

It is preferable to effect coagulation relatively slowly, for exampleunder such conditions that the materials may leave the coagulatingmedium in a more or less plastic state. In this way the materials may beobtained in structurally continuous gel form, without the necessity ofany further treatment. Asdescribed above, coagulation may be delayed bythe incorporation of suitable substances in the spinning solution.Alternatively, or in addition, other means may be adopted to decreasethe rate of coagulation. For example the coagulating medium may containsolvents or swelling agents for the cellulose derivative. Thus I mayemploy aqueous coagulants containing thiocyanates, zinc chloride orother inorganic swelling agents for the cellulose derivative, or organicswelling agents, for example diacetone alcohol, acetic acid, formicacid, as described in U. S. Patents Nos. 1,465,994 and 1,467,- 493, orthe relatively strong solutions of solvents or plasticizing agents of U.S. applications S. Nos. 402,785 filed 26th October 1929 and 418,414filed 3rd January 1930, with or without salts, sugars and the like asdescribed in'U. S. application S. No. 469,622 filed 21st July, 1930. Forexample, a 25% solution of cellulose acetate in acetone which containsalso 6% of ethyl lactate, may be spun into a coagulating bath consistingof 49 parts by weight of ethyl lactate, 2 parts by weight of sodiumchloride and 49 parts by weight of water.

I'prefer to employ aqueous coagulating media such that the materialsremain plastic for some distance along their path and may even emergefrom the coagulating medium in a more or less plastic condition. Othercoagulating media may however be employed. The solution may, forexample, be spun into baths containing paraffin oil, petroleum spirit,petroleum ether, toluene or other hydrocarbons, nitrobenzene or othernitroaromatic hydrocarbons, hexachlorethane or other suitable aliphaticor aromatic halogenated hydrocarbons; or animal or vegetable oils, e. g.castor oil, sesame oil or olein may be employed. The coagulating mediummust naturally be such that it dissolves at least one constituentpresent in substantial proportions in the spinning solution, and is anon-solvent for the cellulose derivative. As in the case of aqueouscoagulating media, so in non-aqueous media solvents or swelling agentsfor the cellulose derivative may be present.

It is of very considerable advantage to employ coagulating -media ofrelatively high viscosity. Baths containing a large proportion ofmineral acids, e. g. sulphuric acid, mineral acid esters, e. g. ethylsulphuric acid, or other products resulting from the sulphonation orsulphation of organic compounds, e. g. benzene sulphonic acid, Turkeyred oil, Twitchells reagent and sulphonated brown coal oil are valuablein this respect. The viscosity of the coagulant may be increased by theaddition of suitable substances thereto. A large variety of substancesis available for this purpose; In the case of aqueous coagulants I havefound that valuable results may be obtained by the addition ofcarbohydrates and other polyhydroxy compounds, e. g. starch, sulphitecellulose waste lye and other poly-saccharides, sucrose, molasses,glucose, lactose, mannitol, dulcitol and glycerol. Thus a spinningsolution consisting of 25% of cellulose acetate dissolved in acetone maybe spun into an aqueous coagulating bath consisting of by weight ofdiacetone alcohol, 30% by weight of glucose and by weight of water. Theparticular substances selected must, of course, be compatible with theother constituents of the coagulating medium.

The spinning solution may be extruded directly into a body of liquidflowing counter to the direction of extrusion. It is however preferableto extrude into a substantially stationary body of liquid and to passthe partly coagulated threads directly therefrom into the moving liquidin which coagulation is continued or completed. The materials may, forexample, be formed by spinning into a bath in which the coagulant ispractically at rest, and may be' carried thence without passage throughthe air into a column of liquid moving so as to oppose the travel of thematerials. On the other hand, the spinning jets or dies may be situatedin a dead zone in a body of moving liquid, i. e. in a region in whichthe coagulant is substantially stationary. Such a dead zone can becreated by any suitable means, for example by arranging baflle plates todivert the flow of liquid from the neighborhood of the jets,

or by constructing the spinning vessel of suitable shape to produce thiseffect. The extent of this dead zone may with advantage be such that thematerials, by the time they emerge from it into the region of movingliquid, have undergone coagulation to an extent which renders themsufiiciently strong to withstand a relatively high tension. When aplurality of spinning orifices is so arranged that the materialsextruded converge and thereafter pursue a common path, the transitionfrom the dead zone into the region of movement may be effected beyond orin the neighbourhood of the point of convergence. When the materials areextruded directly into a counter-current of coagulant without passingthrough any intermediate dead zone, the velocity of the liquid in theneighbourhood of the jet should be such that the materials extruded arenot subjected to a greater stretch than they are able to bear. At nopoint in their path, in fact, should the materials be subjected to atension approximating to the maximum which they are able to withstand atthat point.

The coagulating liquid will not be entirely stationary in theneighbourhood of the spinning jets, or at any point along the path ofthematerials, since the composition of the coagulant must be maintainedthroughout the process within the, limits necessary to ensureregularity. The movement caused by the continuous or intermittentreplenishment of the coagulant may however be very slight.

The materials may, if desired, be extruded into a body of liquid flowing(preferably relatively slowly) in the direction of extrusion, and maythen be carried directly through a body of liquid flowing counter to thedirection of travel of the materials. The passage of the materialsthrough the counter-current may take place at any stage in thecoagulation processes, or the liquid drag may be applied even aftercoagulation is complete. a

The path of the moving body of liquid may be determined by confining itin any suitable manner, as, for example, within the walls of a suitablyshaped vessel. Thus for example the liquid may fiow through cylindrical,conical or other suitably shaped enclosed vessels, or through suitablyshaped open baths or channels. The velocity of the liquid may beuniform, or may vary gradually or abruptly along the path of thematerials. Thus for example the cross section or bore of the vesselthrough which the liquid flows may decrease or increase gradually orabruptly, so as to introduce a corresponding increase or decrease in thevelocity of flow over any desired part of the path. Again the velocityat any point in the path may be increased by injecting fresh liquid, ordecreased by removing a part of the liquid, in the neighbourhood of thatpoint.

The tension necessary to draw the materials through the. counter-currentmay be applied in any suitable way, for example by means of positivelydrivenguid'e rolls or other tensioning devices situated along the. path.of the. materials, or by means of any suitable: collecting device.-

The invention may be carried out in a very simple way by extruding in anupward or downward direction into a bath or trough containing abody ofcoagulant substantially stationary in thez neighbourhooda of the jets,and passing the extruded materials. therefromin. an upward direction.through a-descending body of coagulant. The descending stream ofcoagulant may flow through a cylindrical or other suitably shapedenclosed vessel or through an open vessel, forexamplean: open channelinclined at a suitable: angle, s'aid vesselsibeing, suitably supportedabove the'trough into which the coagulant flows. The coagulant mayoverflow or be drawn ofi from the. bath or trough in any suitablemanner. Again, the materialsformed by extrusion may pass downwards.through a stationary column of liquid supported above the trough byatmospheric' pressure, and: may be carried through the trough into acolumn of. liquid flowing counter touthe direction of the materials.Alternatively the jets-may be so situatedthat'the materials pass firstintoa column of liquid flowing in the direction of extrusion, forexample vertically downwards, and are carried by the flow of liquid intothe bath, whence they are drawn ofi through a counter-current ofcoagulant as previously described.

,In order to obtain theadvantages of extruding into a body of liquidsubstantially at rest or moving inthe direction of extrusion, andpassing the materials therefrom into the counter-current, it is notnecessary for the jets to be situated in an open bath or trough asdescribed above. Thus, for example, the jets may be situated in a sidetube entering the main vessel, through which the counter current flows,at any angle; the liquid in the side tube may be substantially at restormay move in the direction of extrusion, so assisting the passage of thematerials into the main vessel. Where, for example, the descendingcolumn of coagulant flows through the main vessel, which should in thiscase be enclosed, the side tube in which the jets are situate-d may beclosed at the end, suitable meansbeing provided for replenishing thecoagulant, and the liquid therein may be substantially at rest or mayflow into the main vessel. Onthe other hand, the side tube may be openat the top, in which case it must slope downwards into the main vessel.The main vessel and side vessel may have any desired form. They may forexample be of circular cross-section, and the cross-section may varyalong their length as. desired. I

The principle of the type of apparatus described above may be applied invarious ways. For example the spinning vessel may comprise three limbsin the form of a Y or an inverted Y, the arrangement being such that thecounter-current of liquid flows through two of these limbs while theextrusion takes place in the third limb, in

which the coagulant may be substantially at rest or may flow in thedirection of extrusion. The materials formed in the third limb are drawnout through the limb by which the. counter-current of liquid enters.In'an alternative form of apparatus open channels constitute the twoupper limbs ofthe Y- shaped spinning vessel.,-

The arrangements described above are such thatthe materials passimmediatelyfrom the region in which the jets are situated to'that inwhich they are subjected to the drag of a counter-- current ofcoagulating liquid, without leaving the liquid. This is not, however,essential to the process. The jets may for example be situatedinthezcounter-curren't itself provided the velocity of said, current issuitably controlled, so as not to be too great inthe neighborhood of thejets. On the other hand the materials may pass out of the body of liquidin which extrusion. occurs before entering the counter-current.Thus'extrusion may be effected in a suitable vessel in which thecoagulating liquid'is substantially at rest or is moving with relativelysmall velocity in the direction of extrusion, andthe materials may passthrough the: air before encountering the stream of coagulant in whichthe liquid drag is applied. When this arrangement is adopted it. ispreferable that the air path should be relatively. short, and that'the'conditions should be such that the materials entering the countercurrentof the coagulant are in a relatively plastic condition. Any godet orsimilar device employed in carrying. the material from the extrusion.bath into the bath in. which the liquid drag is applied should notitself exert an excessive tension on the materials. In a simple form ofapparatus in which the materials pass through the air before meeting thecounter-current of coagulant, extrusion occurs in a cylindrical, conicalor other suitably shaped vessel through which a current of coagulantdescends relatively slowly. The materials emerge through a small orificeat the bottom of this vessel, and pass over a suitable rotating guidepositively driven at such a speed as to exert little or no tension uponthematerialsand are then carried in an upward direc-' tion through acylindrical. or conical vessel down which a current of. liquid isflowing with such velocity as. to exert the required. drag upongthematerials; ,The materials are withdrawn at the top of this vesselv bymeans. of any suitable drawing off device.

The flowof the coagulant'may. be produced by any suitable means, forexample, by the use of a sufficient head of liquid, or by the action ofin: jectors,f ejectors or pumps. The arrangements maybe such that a.proportion of the coagulant circulates continuously through theapparatus, further coagulant being introduced at some point in thecircuit, and a corresponding amount of spent coagulant beingcontinuously drawn off.

The velocity of, the coagulant at any point in the path of the materialswill in general be maintained constant, when once the process has beenset in operation. In starting however, it is of advantage to set theliquid throughout the whole system moving in such a direction astoassist the travel of the materials towards the collecting device. Thenwhen the collecting device has commenced to draw off thematerials,thevelocity of flow in the various parts of the system may be adjustedas finally required. The system should, therefore be designed so thatvariation of the velocity of flow can be simply effected, and in.particular so that where during normal work,- ing, the liquid vflowscounter to the direction of travel of the materials in starting up saidliquid may remain at rest or move in the same direction as thematerials. In order toproduce particular effects, the velocity of thecoagulant may be varied during the normal working of the process. Thusfor example filaments and the like of variable denier may be produced'byinter mittently varying the velocity of flow otthecoagqulant. Thisvariation may'take place at regular or irregular intervals. A similareffect may be produced by varying the velocity of the spinning pumps, asdescribed in U. S. application S. No. 390,400 filed 4th September, 1929.

In carrying out the invention each coagulating bath, funnel or otherform of coagulating vessel may be provided with one, two or more jets.These may be multiple jets or, especially in case it is required tospinmaterials of very heavy denier, e. g. bristles, ribbons and the like,single jets. The jets or dies may be of any suitable form. Where thecoagulating vessel is provided with two or more jets it is of advantageto isolate the materials issuing from the-respective jets.

Coagulation of. the materials may or may not be completed before thematerials leave the counter-current of coagulant liquid. It is howe everof advantage for the materials to retain some degree of plasticity afterleaving the coagulating liquid or even throughout the whole of theirpath to the drawing off device. The materials may pass from the vesselin which the liquid drag is applied into one or more further treatmentbaths which may or may not contain coagulating. or fixing media. Afurther stretch may if desired be applied in such subsequent treatmentbaths. In these baths also the liquid may be caused to move in adirection such as to resist the travelof the materials. In applying thecounter-current principle to further treatment baths, substantially thesame considerations arise as when the principle is applied to thecoagulating baths. As in the coagulating baths so in further treatmentbaths the velocity of the counter-current employed will depend on theviscosity of the treating liquid and the plasticity of the vmaterials.It will usually be advantageous in further treatment baths to employ aliquid of greater viscosity and/or flowing at a higher velocity than theliquid in the coagulating baths. The treating baths may be designed soas to permit of varying. the velocity of the moving liquid in the sameway as has been indicated in the case of spinning baths.

The process of stretching the materials by drawing them through acurrent of liquid flowing so as to oppose the travel of the materials,though described above as a step in a wet spinning process, may beapplied to filaments, threads, yarns, films and the like continuouslywith their production by any spinning process. Further the process maybe applied to fully formed or finished materials, which may be softenedor plasticized with a view to facilitating stretching. The materials mayfor example be passed through or immersed in a bath containing anysuitable swelling agent for the cellulose derivative. I prefer to softencontinuously with the drawing of the material through thecounter-current. Where a softening agent is employed, the nature of saidagent, the length of time during which the material is'in contacttherewith and the temperature, will naturally be such that a sufficientdegree of plasticity is induced in the materials to permit of thestretching operationbeing eifected. In generalthe time and/ orconcentration may be decreased with increasing temperature. In ap plyinga softening treatment prior to or as a separate operation from thestretching process, a relatively high concentration of solvent may beobtained on the filaments or other materials by applying a more dilutesolution of a the solvent in a volatile diluent, and producing the highconcentration by evaporation of the diluent. Thus,

for example aqueous solutions of the relatively non-volatile organicliquid reagents referred to below may be allowed to dry in or evaporateon the materials. The concentration of the reagents or the conditionsunder which they are applied may be varied with the type of materialbeing treated and with its cross-section. When the material passes firstthrough a softening bath and then through the air into the stretchingbath, the boiling point of the softening liquid should not be so lowthat all or substantially all the liquid evaporates from the materialbefore the stretching bath is reached.

The air path between softening and countercurrent stretching baths maybe very short or may be eliminated altogether, but even in this case itis of advantage to employ softening agents of moderately high boilingpointin order to minimize losses due to evaporation. 1

Any suitable softening agent may be employed. Among those available maybe mentioned acetone, methyl ethyl ketone, cyclo hexanone and otherketones, butyl acetate, ethyl lactate, diethyl tartrate, monoordi-ethersof glycols generally, for example ethylene glycol mono-methyl ether anddioxane, dibutyl tartrate and other aliphatic esters, diacetone alcohol,phenol, thiocyanates, zinc chloride and other inorganic swelling agents.Mixtures of such agents maybe employed, for

instance mixtures of acetone and diacetone al- 9 cohol. The softeningagent may be diluted with a non-solvent liquid or diluent, for instancewater, benzene or the like. The concentration of the softening agentwill depend to some extent on the solvent power of the agent used. Byway of example I may mention that diacetone alcohol, diethyl tartrateand ethyl lactate may be employed in aqueous or alcoholic solution in aconcentration of above 25%, and in fact very good resultsare obtainedwith concentrations of 25 to 65% strength.

Preferably the softening agents employed are such that by reason oftheir innocuous properties they need not be washed out of thematerialsand can remain therein to be removed by evaporation only. Good resultsare obtained with relatively non-volatile neutral organic solventsdiluted with a non-solvent diluent, for example aqueous'solutions ofdiacetone alcohol, diethyl tartrate, monoor di-acetin or ethyl lactate.

The moving liquid in the counter-current stretching baths may be such asto harden the materials. Thus liquids which are non-solvents for thecellulose derivative but solvents for the softening liquid may beemployed. It is preferable however to employ for the counter-currentliquids having a softening effect. The materials may then undergoa'hardening treatment after emergence from the stretching baths. Thismay for example consist in removing any softening liquid remaining inthe materials by means of heat or'through the action of a suitabletreat.- ing liquid. The process may be carried out so that the materialsretain some degree of plasticity after emerging from the counter-currentstretching baths. Whatever the nature of the liquid employed in thecounter-current stretching baths it should preferably have a highviscosity.

The materials may be collected and/or twisted by any suitable means.They may, for example, be collected in a spinning box, or wound on abobbin, swift or other package. The tension necessary to draw thematerials through the counter-current may be applied by the collecting.device alone or assisted by any other suitable the materials. I

means-such, for instance, as positively driven guide. rolls-suitablysituated along the path of the materials. When the materials aresubjected to a further liquid treatment after leaving thecounter-current, the treating liquid may be caused; to flow in thedirection of travel of the materials,-as describedin U. S. Patent No.2,027,- 419 of January .;14, 1936'filed 16th January, 1931 and may inthis way supply at least a part of the required tension. Theactualtension exerted in this Way will of course depend on the velocityof flowfand the viscosity of the liquid in the treating bath. Where thetreating agent itself does not possess the desired viscosity, suitablesubstances maybe added to the bath to increase the viscosity. When'thepath of the materials is relatively long it is particularly advantageousfor the tensionexerted by the collecting device to be supplemented, bysuitable means along said path. Further, such means may provide thewhole of the tension required, the collecting device being driven atsuch a speed as to'exert .notension on Before collecting the materialson bobbins, in spinning boxes .etc., their plasticity should besufficiently reduced to prevent coalescence-on the package. Preferablysubstantially the whole of the solvent or swelling agent is removedbefore collecting. I The materials may be subjected continuously withthe stretching process of the invention to anydesiredafter-treatment.They may for example be-so treated as to modify their lustre,

or to produce metallic or other effects; they. may

be, coloured in'fast shades, or a fugitive colouration maybe impartedfor purposes of identification; theywma-y beweighted, mordanted, saponisfied or otherwise treated so as to modify their dyeing properties; theymay be subjected to sizing or other processes designed to facilitatesubsequent textile treatments. I

When the process of the invention is'applied tcgthe productionof thematerials by a spinning process, various effects may be obtained byvarying the composition of the spinning solution. Finely dividedrelatively insoluble inorganic or organic substances, for example finelydivided barium sulphate or :titaniumoxide, may be incorporated in thespinning solution-according for example to the processes of U. S.applications S. Nos. 444,622'filed 15th April 1930, 464,122 filed 26thJune .1930, 473,781 and 473,782 filed 7th August 1930, and 488,829-filed15th October 1930, or may be formed in the materials by interactionbetween a soluble salt contained in the'spinning solutionzand'acons-t-itue-nt of the coagulating liquid. Thus for example bariumsulphate maybe fannedwithin the materials by incorporating bariumthi-ocyanate in the spinning solution :and spinning into a bathcontaining sulphuric acid or a sulphate. In this way products of subduedlustre may be obtained. Processes for obtaining such effectsare-described in U. S. application S. No. 303,602 filedlstSeptember,1928.

The pinning solution may contain nonsolvents compatible with the solventmixture, for example paramn oil, petroleum ether or other by droearbons,cas-toroil or other animal or vegetable oils. wOther substances may beincorporated ,in-the spinning solution in order, for example, tofacilitate the spinning process or to improve the properties of the productin some-particular respect. Where the spinning solution containsnon-solvents for the cellulose derivative these should not, 'o;f-.course,-hepresent in .suflicient cation S. No. 316,617 filed 1stNovember 1928, or

by maintaining the temperature of the coagulant above the boiling pointof .a constituent of the spinning solution hollow filaments may beobtained, as is also described in this specification. If. desired, atemperature difierence may be maintained along the path of the materialsin the spinning bath and/or in any subsequent treatment baths.

Various types of apparatus suitable for carr'yingout the presentinvention are shown on the annexed drawing, but it is to be clearlyunderstood that they are given only by way of illustration and that theinvention is'in no way limited thereto. 7 I

In the accompanying drawing: Figs. 1 to 4 show diagrammatic views ofapparatus suitable for carrying out the invention in which drag isexerted .on the filaments by a liquid medium at least part'of which.moves countercurrent to the direction of travel of the filaments. V 3

Fig, 5 isasectional view along the line- B-B of Fig. 4.

f Fig. 6 shows another form of apparatus in which the coagulating mediumin the; region .of the jet flowsnin the direction of travel of .thefilaments. Fig. 7 is a sectional view along the line A-A ofFig. 6. Fig.8shows a form of apparatus-suitablefor the treatment of formed filamentsor other products.

Fig. 9 shows a form of apparatus suitable for use in the stretching offormed filaments .orother products continuously with their production bydry spinning methods. v Fig. 1 shows an apparatusconsisting of acylindrical vessel ill into which a bundle of filaments i2 is. extrudedupwards through a spinning jet ii. A coagulating liquid is introducedthrough a pipe M by means of an annular channel which surrounds theupper constricted portion of a funnel 63, This upper portion may be ofany desired length, and in order that this may be clear it is shown asbroken in each of the illustrations. The bundle of filaments passesupwards through the funnel and meets a, counter-current of graduallyincreasing velocity, until it enters the narrow portion of the funnelwhere the maximum force of the moving liquid is exerted. It passesupthis channel over a guide and is taken up onthe roller or bobbin IS.The coagulating medium issues from the vessel through the outlet l5.

Fig; 2 shows a similar form of apparatus but in this case the bundle offilaments l2 extruded from the jet H passes through two funnels l3 andH, the bottom one of which is either positioned close to the base of thevessel l0, o'relse, as shown in the illustration, supported actuallyupon the base. In this latter case the bottom of the funnel is formedwith openings of a semicircular or other convenient shape, as is shownin Figs. 4 and 5, so that a small quantity of the coagulating liquid mayflow through this funnel. In this manner the medium surrounding the jetis renewed sufficiently frequently for uniform coagulation of thefilaments to be obtained, while at the same time the counter-current inthe region of the spinning jet is reduced to a very small amount. As inthe previous illustration the liquid medium is introduced through a pipeI4 and flows out at the bottom of the vessel through a pipe l5.

' Another form of apparatus is shown in Fig. 3, in which the containingvessel I is itself made with its upper part in the form of a funnel. Thespinning jet II from which the bundle of filaments I2 is extruded issurrounded by a cylindrical partition I9 which serves to protect thefilaments, during the first stages of their coagulation, from the fullforce of the counter-current. The coagulating medium entering throughthe pipe I 4 leaves the vessel through the pipes I5 and I8, and bysuitably dimensioning these two outlets the ratio of the volumes ofliquid issuing from them may be adjusted to any desired amount. Forexample, by making the outlet I8 of relatively small dimensions thevolume of liquid flowing from the cylinder I9, and consequently thecounter-current in the region of the jet, may also be kept small.

Fig. 4 and Fig. 5, a cross-section on the line B--B of Fig. 4, show aform of apparatus which may be employed when it is desired to exert arelatively large tension upon the filament, or when a coagulating mediumof relatively small viscosity is employed. In this modification thecoagulating medium entering through the pipe I4 passes through aninjector device 23 so that a suction is exerted and some of the liquidin the vessel I0 is drawn into the pipe. When this modification isemployed, a suitable head of liquid may be maintained above the level ofthe injector device by controlling the rate of inflow and outflow of thecoagulating medium through the pipes I4 and I5. The main body of liquidintroduced by the injector device 23 passes down the funnel I3 into thebody of the vessel I0 and out through the pipe I5. Concentric with thispipe I5 is a smaller pipe 2!] connected by an annular channel withanother funnel I1. In consequence of the liquid flow through I5 suctionis exerted at the outlet from the pipe 20 so that the liquid iswithdrawn from the funnel II. In this manner a relatively small fiowdown theupper narrow portion of the funnel I1 is induced, and also aslight upward flow from the bottom of the funnel through the openings 22in the direction of movement of the bundle of filaments I2. Asemi-circular bafile plate 2! is inserted in order, to prevent an upwardflow towards the outlet I 5 causing a turbulent flow in the funnel II.

Fig. 6 and Fig. '7, a cross-section on the line AA of Fig. 6, showanother form of apparatus in which the coagulating medium in the regionof the jet II flows in the direction of travel of the filaments. Theapparatus consists of a cylindrical vessel II], the upper part of whichhas the shape of a funnel. Two inlets for liquid medium are provided,one I4 in the upper constricted portion of the funnel, through which theliquid flows in a downward direction, and the other 25 in the base ofthe vessel, the liquid introduced at this point flowing upward in thedirection of travel of the filaments. In this form of apparatustherefore the bundle of filaments I2 extruded from the jet II passesfirst through a current of liquid moving in the direction of theirtravel, and afterwards through a countercurrent in the upper part of theVessel. The coagulating medium issues from the vessel by the pipe I5,and in order to prevent the outflow from producing a lateraldisplacement of the bundle of filaments a suitable baflle 24 isprovided.

Fig. 8 shows a form of apparatus for the treat ment of formed filamentsor other products. The filaments 26 are unwound from a bobbin 2'! or aswift or other device, and are passed in an upward direction through theopening I5, from which the stretching liquid introduced through the pipeI4 issues. The filaments or other products may have been previouslybrought to a plastic condition by treatment by immersion in a suitableliquid or by any other suitable method, or a liquid having aplasticizing or softening action on the filaments may be used to producethe stretching force.

Finally, Fig. 9 shows a form of apparatus which may be applied to thestretching of filaments or other products continuously with theirproduction by dry spinning methods. The filaments 36 issuing from thedry-spinning cell 35 are passed round a draw-roller 31 and a back guide38, over or round a roller 28, where they are treated with aplasticizing medium by means of a spray 29, and then down the vessel 3|,through which a suitable liquid medium, introduced by an inlet pipe I4,passes upwards and out through the pipe I5. After issuing from thevessel 3| the filaments pass over a guide 39 and then round adraw-roller 33 which exerts a stretching force. At the same time theyare washed by means of the liquid from the spray 32. The vessels 30 and34 serve to collectand carry off the excess liquid.

What I claim and desire to secure by Letters Patent is:''

1. Process for the manufacture of artificial filaments, threads,ribbons,films and similar materials which comprises extruding a spinningsolution containing cellulose acetate into a liquid medium, which, inthe neighborhood of the jet, moves in the direction of travel of thematerials to form materials having a continuous'stnict ure; andwithdrawing the materials by means, of a suitable drawing device,through a body of liquid moving so as to exert a drag upon thematerials.

2. Process for the manufacture of artificial fila; ments, threads,ribbons, films and similar materials, comprising extruding a spinningsolution containing an organic derivative of cellulose into a liquidmedium to form materials having a continuous structure, said liquidmedium moving counter to the direction of the materials so as to exert adrag thereon, drawing the materials through said liquid medium by meansof a drawing roller and conducting the materials to a winding device onwhich they are wound.

3. Process for the manufacture of artificial filaments, threads,ribbons, films and similar materials, comprising extruding a spinningsolution containing cellulose acetate into a liquid medium to formmaterials having a continuous structure, said liquid medium movingcounter to the direction of the materials so as to exert a.

drag thereon, drawing the materials through said liquid medium by meansof a drawing roller and conducting the materials to a winding device onwhich they are wound.

4; Process for the manufacture of artificial filaments, threads,ribbons, films and similar materials, which comprises extruding aspinning solution containing an organic derivative of cellulose into aliquid medium to form materials having a continuous structure, saidliquid medium being in the neighborhood of the jet substantiallystationary and in another part of its path moving counter to thedirection of the materials so as to exert a drag thereon, drawing thematerials through said liquid medium by means of a drawing roller andconducting the materials to a winding device on which they are wound.

5. Process for the manufacture of artificial filaments, threads,ribbons, films and similar materials, which comprises extruding aspinning solution containing cellulose acetate into a liquid medium toform materials having a continuous structure, said liquid medium beingin the neighborhood of the jet substantially stationary and in anotherpart of its path moving counter to the direction of the materials so asto exert a drag thereon, drawing the materials through said liquidmedium by means of a drawing roller and conducting the materials to awinding device on which they are wound.

6. Process for the manufacture of artificial filaments, threads,ribbons, films and similar materials, comprising extruding a spinningsolution containing an organic derivative of cellulose into acoagulating bath containing a substantial proportion of a substancecapable of softening the cellulose derivative to form materials having acontinuous structure, said coagulating bath moving counter to thedirection of the materials so as to exert a drag thereon, drawing thematerials through said coagulating bath by means of a drawing roller andconducting the materials to a winding device on which they are Wound.

7. Process for the manufacture of artificial filaments, threads,ribbons, films and similar materials, comprising extruding a spinningsolution 7 containing cellulose acetate into a coagulating bathcontaining a substantial proportion. of a substance capable of softeningthe cellulose acetate to form materials having'a continuous structure,said coagulating bath moving counter to the direction of the materialsso as to exert a drag thereon, drawing the materials through saidcoagulating bath by means of a drawing roller and conducting thematerials to a winding device on which they are wound.

8. Process for the manufacture of artificial filaments, threads,ribbons, films and similar materials, which comprises extruding aspinning solution containing cellulose acetate into an aqueous mediumcontaining a substantial proportion of a softening agent for celluloseacetate so as to form materials having a continuous structure, saidmedium moving counter to the direction of the materials so as to exerta. drag thereon and drawing the materials through said medium by meansof a drawing roller and conducting the materials to a winding device onwhich they are wound.

HENRY DREYFUS.

;' column, line 8,

CERTIFICATE OF CORRECTION.

September 22, 1936.

Patent No. 2,054,852.

HENRY DREYFUS.

printed specification or Page 5, first 1951"; and that therein that theIt is hereby certified that error appears in the the above numberedpatent requiring correction as follows:

strike out the words "filed 16th January,

tent should be read with this correction the record of the case in thePatent Office.

his 3rd day of November, A. D. 1956 the said Letters Pa same may conformto Signed and sealed t Henry Van Arsdale Acting Commissioner o Eatent e(Seal)

